It was a wild front nine for Thompson, with only three pars, which ordinarily would spell disaster on a day like this except for his putting.
He made a 50-foot eagle putt on the third hole, made a 12-foot birdie putt behind the hole at the par-3 fifth hole and hit an approach into 4 feet for birdie on the eighth. Just as big was the tough sixth hole, where Thompson hit a bunker shot 18 feet over the flag and made the par putt coming back.
Guthrie, who fell behind for good with a bogey on the second hole, did his best to stay in range until hitting his tee shot out of bounds on the 14th for a double bogey. From there, it was only a battle for second place.
Everyone else was long gone.
Westwood failed to save par on consecutive holes on the front nine and could never catch up. Charles Howell III, who started the day three shots behind and needed a win to get to the Masters in his hometown, fell apart on the back nine with a 41 and closed with a 78.
He at least gets into Doral next week through his FedEx Cup standing. Rickie Fowler made three bogeys on the first six holes and was never a factor.
Thompson's short game was superb during the pivotal part of the final round. He twice chipped to tap-in range for par on the 10th and 11th holes, and he built a four-shot lead with four holes to play. The only thing that kept him from an easy walk to this first win was Ogilvy's late birdies.